1. Field of the Invention
The present invention relates to a printed-matter issuing managing system which issues printed matters that should be protected against their forgery, falsification, reproduction and the like, such as cash vouchers having cash values, securities and official and private documents having descriptions on rights and duties in the law of property, and which judges the authenticity of printed matters.
2. Description of the Related Art
With progress of the internet technology, a conventional system which is constructed with a private line, terminal equipment, and dedicated printers, including a system for issuing cash vouchers such as concert tickets, railway tickets and airplane tickets, will be superseded by a system constructed with the internet opened to everyone, commercially available computers and printers. Further, a conventional system not utilizing the network will also be superseded by a system utilizing the internet. For example, in the United States of America, electronic stamps are under test operation by Neopost corporation, E-Stamp corporation, StampMater corporation, etc., and will be in practical use. The electronic stamp is a system in which a user acquires cash value information indicating a stamp charge and prints a stamp mark as a postage stamp on an envelop, a postal card or a postcard, using a personal computer and a printer that are commercially available. The electronic stamp may be used as a postal stamp like the currently and generally used stamps.
In using a network that anyone can access, like the internet, the illegal actions are likely to occur. For example, a malicious third party wiretaps or alter the data, and further poses as the other party of communication to transmit and receive the data. In case where a monetary value information is handled on such a communication system, there is the necessity of preventing the data wiretapping and alteration, and preventing the malicious third party from posing as the other party. Various techniques for preventing the data wiretapping and alteration, and the pretense have been developed. Specific examples of such techniques are the digital signature or the electronic authentication by use of the public-key and common-key encryption techniques. For the digital signature or the electronic authentication by use of the public-key and common-key encryption techniques on the internet, reference is made to, for example, “Digital Signatures and Encryption” (published by Prentice Hall corporation).
In the case of an image data, an electronic watermark technique is known for preventing the illegal reproduction or alteration of the image data. In the technique, “watermark” is electronically embedded into the image data. The watermark technique is described in “Encryption System in Multimedia Era” (Maruyama Gakugei Tosho, in Japan), for example.
Further, there has been developed a mark into which a verification information is embedded by the electronic watermark technique, as a tool for verifying the authenticity of a home page on the internet. This mark prevents the illegal action, alteration and reproduction by use of the electronic watermark technique. If the printed matter is illegally altered or reproduced, a verification software, which is developed as means for checking the illegal actions of alteration, reproduction or the like, operates, and drives warning means to prohibit the mark from being displayed or overlays a mark “X” on the mark. The user sees it on the display screen, and can easily find out the illegal alteration. This technique is described in “Study and Development on the Techniques on Bona Fide of Internet Home Pages” (Communication/Broadcasting Organization).
The above-mentioned system constructed with the internet and terminal devices available in the market is designed to be used in a situation beyond the control by the issuers, such as homes, offices and public area. Accordingly, there is a chance that the user illegally issues printed matters, and uses the illegally issued printed matters.
To cope with this, Japanese Patent Laid-Open No. 11-78176, entitled “PRINTED MATTER PUBLICATION CONTROL SYSTEM, PRINTED MATTER PUBLICATION CONTROL METHOD AND PRINTER”, proposes the printed matter issue control system and method for preventing illegal printed matters from being issued. In this technique, ID information is assigned to the printing recording medium in advance. The ID information assigned to the printing recording medium is related in advance to the information (referred to as “contents”) to be printed on the printing recording medium. At the time of printing, the system reads the ID information of the printing recording medium by using a printer capable of reading the ID information from the medium, and judges if the medium is true, and if it is true, the printer prints the contents thereof. If no ID information is present or the printing recording medium or the printing recording medium corresponding to the ID information is already printed, it is judged that the medium is false, and the medium is not printed. In this way, the technique prevents the illegal printed matter from being issued.
The technique disclosed in Japanese Patent Laid-Open No. 11-78176 allows the contents to be printed on the true printing recording medium, and capable of preventing formation of printed matters having the same contents by the utilization of the ID information recorded on the printing recording medium as is printed. After the printing ends, the technique merely makes invalid the printing based on the same ID information as that recorded on the printing recording medium. When the contents printed on the printing recording medium is altered, the technique is incapable of judging whether the printed contents are true or false.
Japanese Patent Laid-Open No. 2001-134672 discloses a technique of judging an authenticity of an electronic sheet. The technique utilizes an electronic sheet as a printing recording medium having an IC chip integrated thereinto. The electronic sheet allows information to be printed on the surface of the sheet per se. The IC chip allows information to electronically be written into and read out of the chip per se in non-contact manner. A certify key is written into the IC chip. The technique judges if the electronic sheet is true or false by use of the certify key. Since the technique of Japanese Patent Laid-Open No. 2001-134672 judges if the electronic sheet is true or false by using only the certify key at the time of verification, a verifying device cannot judge if the prints are falsified in case where information as properly printed on the electronic sheet is altered in some manner.